The first variant to appear carried a D614G mutation in the spike protein 11 which is now dominant and shared between all existing variants. The situation has been exacerbated by the fact that SARS-CoV-2 has evolved considerably. Further, a significant proportion of infected individuals either remain entirely asymptomatic or only manifest mild symptoms 6, 10, thus facilitating the spread of the virus and leading to the current pandemic. The viral load peaks soon after the onset of symptoms 7, 8, 9, suggesting that individuals with COVID-19 begin viral shedding a few days before symptoms appear.

The quick diffusion of SARS-CoV-2 is primarily attributed to the relatively long duration of viral shedding by infected individuals, the viral load dynamics and the lengthy incubation period of 5-6 days 4, 5, 6. COVID-19 is a respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 2, 3. Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, 486 million confirmed cases, including 6.1 million deaths, have been reported globally as of Ap1. Altogether, ADESSO is a fast, sensitive and cheap method that can be applied in a point of care setting to diagnose COVID-19 and can be quickly adjusted to detect new variants.

Using an extensive panel of clinical samples, we demonstrate that ADESSO correctly identifies infected individuals at a sensitivity and specificity comparable to RT-qPCR on extracted RNA and higher than antigen tests for unextracted samples. To address these needs we developed the diagnostic test ADESSO (Accurate Detection of Evolving SARS-CoV-2 through SHERLOCK (Specific High Sensitivity Enzymatic Reporter UnLOCKing) Optimization) which employs Cas13 to diagnose patients in 1 h without sophisticated equipment. Moreover, the emergence of variant strains creates the need for flexibility to correctly and efficiently diagnose the presence of substrains. However, these methods suffer from either general applicability and/or sensitivity. During the ongoing COVID-19 pandemic, PCR testing and antigen tests have proven critical for helping to stem the spread of its causative agent, SARS-CoV-2.

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